updated 07:35 am EDT, Tue August 24, 2010

Sony A33 and A55 promise 10FPS continous shooting

Sony kicked off a slew of Alpha camera launches today with its flagships, the A33 and A55. The two are the first to use translucent mirrors that let light hit both the autofocus and image sensors; the move allows the cameras to refocus even while the sensor is taking the previous shot. Using the mirrors not only improves the burst shooting speed, up to 10FPS for the A55, but makes the camera smaller as it doesn't have to have room for flipping the mirror.

Combined with a new 15-point autofocusing system, the Alphas can maintain continuous phase detect AF and the option of constant auto exposure adjustment as well. The two are some of Sony's first DSLRs to record video and capture AVCHD (H.264) and will record 1080i video with continuous phase detect AF.

In more conventional areas, both have electronic viewfinders with 1.1X magnification, which allows movie recording while getting a preview through the eyepiece, and a three-inch, 921,000-pixel swiveling LCD. They support Sony's 2D and 3D sweep panorama modes as well as multi-shot modes to produce high dynamic range or lower the perceived noise.

Differences between the cameras are dictated mostly by sensor size and performance. The A33 as the starter shoots at 14.2 megapixels and up to 7FPS. Moving to the A55 upgrades both to the full 10FPS burst shooting and a 16.2-megapixel sensor. Either has the choice of using Memory Stick Duo or SD/SDHC/SDXC cards, and Sony now has a pair of external microphone options for stereo sound to match the video.

The A33 ships first, arriving in September for either $650 body-only or $750 with an 18-55mm kit lens. A55 deliveries begin in October and will add $100 to both the body and kit prices.